Texas Researcher Explains Evolution of Life
Texas Tech University researcher says that meteorites that hit early earth kick-started life and complex forms took birth in the deep craters formed by the impact.
Origin of life on earth is a mystery that still baffles science. Many theories have been proposed to explain the origins of biological forms. However, none of them independently explain the start of life.
Now, Sankar Chatterjee, Horn Professor of Geosciences and curator of paleontology at the Museum of Texas Tech University, says that he has connected the dots and found how life may have originated.
The idea of life coming from elsewhere isn't new. For decades, it has been hypothesized that life might have originated at some other place in the Universe and accidently landed on Earth.
Ancient craters on Venus and Mars describe the struggle that the planets had to go through during their infant years.
Chatterjee's research suggests meteorites got the essential ingredients to life-building from the distant corners of the Universe.
"When the Earth formed some 4.5 billion years ago, it was a sterile planet inhospitable to living organisms," Chatterjee said in a news release. "It was a seething cauldron of erupting volcanoes, raining meteors and hot, noxious gasses. One billion years later, it was a placid, watery planet teeming with microbial life - the ancestors to all living things."
According to Chatterjee, life began in four steps. It went from cosmic, geological, chemical and arrived at its biological state.
The Cosmic Stage-
Between 4.1 to 3.8 billion years ago, earth was pounded daily by large meterorites. These rocks punched holes in the crust and created geothermal vents. Also, essential life ingredients from other parts of the Universe arrived on earth via these meteorites.
Recently, astronomers have found asteroids could even act as water-delivery systems.
Chaterjee studied fossil-rocks in Greenland, Australia and South Africa and believes that these might have been the places where life first appeared.
The Geological Stage-
Icy comets that came to earth melted due to earth's perfect proximity to the sun. The geothermal vents then heated these water-filled craters and created a thick primordial soup.
"The geological stage provides special dark, hot, and isolated environments of the crater basins with the hydrothermal vent systems that served as incubators for life," he said. "Segregation and concentration of organic molecules by convective currents took place here, something like the kinds we find on the ocean floor, but still very different. It was a bizarre and isolated world that would seem like a vision of hell with the foul smells of hydrogen sulfide, methane, nitric oxide and steam that provided life-sustaining energy."
The Chemical and Biological Stage-
In this stage, the chemicals in the water reacted and formed simple organic molecules.
One can create organic molecules in the lab, but not life. Chaterjee said that the ancient soup had a key biological ingredient- fatty lipid material, which came to earth on space body. Complex biological forms that had the ability to replicate underwent many trials and errors.
"The emergence of the first cells on the early Earth was the culmination of a long history of prior chemical, geological and cosmic processes," he said.